Relatively large reusable containers are utilized by manufacturers to ship a variety of different products to their customers. For example, in the automobile industry, a plant assembling a particular automobile might utilize a number of different parts manufacturers. These manufacturers ship their respective parts to the plant in reusable containers where the parts are then assembled together into a finished automobile. The reusable containers are often returned to the parts manufacturers for use in further shipments.
Generally construction of such shipping containers includes a pallet base, a cover and sleeve pack which is situated between the base and the cover to form the sidewalls of the container. Such a design provides a versatile and lightweight shipping container which may be reused time and time again. The vast majority of sleeve packs used today are made of heavy grades of triple wall corrugated paper, such as paper in the 1,000 lb. bursting strength range. Such paper wall sleeve packs are functional if kept dry; however, as may be appreciated, moisture damages the strength of the paper wall and degrades the overall reliability of the sleeve pack. Accordingly, there is a need for a sleeve pack which can be stored outdoors as necessary when indoor storage space is not available.
Plastic sleeves have been utilized for weatherproof containers; however, even the existing sleeve packs of plastic have undesirable limitations. Specifically, if made of a single layer of plastic, the single layer of plastic making up the sleeves is not capable of achieving adequate stacking strength, and therefore, in many cases, the several sheets of the single wall plastic material have to be laminated together. Often even the laminated sheets are not strong enough to support the stacking loads required, and they have to be reinforced with another material. The increased number of sheets in strengthening layers increase the expense of the containers and the complexity of their assembly.
Sleeve packs, whether plastic or paper, generally require some sort of reinforcement at their corners to hold the sleeve pack sidewalls together and to provide adequate support for the stacked loads. Different mechanisms and techniques have been utilized to reinforce the corners of a sleeve pack.
One of the techniques used to reinforce the corners of a sleeve pack includes wrapping one of the sidewall panels of the sleeve pack over the adjacent sidewall panel, creating a two-ply corner. Two overlapping sidewall panels are then joined by adhering or sonic welding the outer face of the inner sidewall panel to the inner face of the outer sidewall panel where the two sidewall panels overlap. The result is a sleeve pack which has two-ply corners immediately adjacent one ply sidewalls.
A potential problem which occurs with such an overlapped corner sleeve pack is that a vertical side edge of the outer ply protrudes outwardly, and creates a snag which may catch clothes or the edge of a forklift. Another potential problem is that when placing such an overlapping corner sleeve pack into an outer channel of a pallet base of a sleeve pack assembly, the portion of the sleeve pack where the sidewall panels overlap often does not fit into the channel of a pallet base. Either the channel of the pallet base must be increased in size, creating a loose fit of the one-ply sidewalls inside the channel or the two-ply corners of the sleeve pack must be trimmed to fit inside the channel of the pallet base.
Another potential problem with a plastic sleeve pack having sonic welded overlapping corner sidewalls is that the sonic welds used to secure the overlapping portions of the sidewalls are spaced apart and may create a weak joint. If the overlapping portion of a sidewall panel is caught by a forklift the weld may tear, separating the wall panels of the sleeve pack. The contents inside the sleeve pack will then fall out of the sleeve pack assembly and the sleeve pack assembly must be reassembled.
Another potential problem with a plastic sleeve pack having overlapping sonic welded corner side walls is that it is difficult to make the sidewalls of the sleeve pack of accurate dimensions. The overlapping side wall panels are subject to slipping during the sonic welding process, resulting in sidewalls longer or shorter than desired.
Still another potential problem with plastic sleeve packs having overlapping sonic welded side wall panels is that because the sonic welds are spaced apart or separated, the seal is not always water-tight and water may enter between the welds of overlapping wall panels. Water inside the sleeve pack is undesirable because the moisture may corrode or rust the parts located inside the sleeve pack assembly.
Yet another potential problem encountered in the use of sleeve packs occurs because of the inability of the sleeve pack to withstand a horizontally impact force applied to one of the corners or sidewalls of the sleeve pack. As a result, when a forklift hits the sidewalls or corner of the sleeve pack, as often occurs, the sleeve pack sidewalls may collapse inwardly and become permanently deformed.
Still another potential problem with existing sleeve packs occurs in identifying product contained within the sleeve pack. Once a sleeve pack is inserted between a cover and a pallet base to make a sleeve pack assembly the sleeve pack assembly has no identifiable characteristics to mark or identify the contents inside the sleeve pack assembly. A manufacturer receiving multiple sleeve pack assemblies, each sleeve pack assembly containing different parts, must look through each individual sleeve pack assembly to find the particular part desired. Since many sleeve packs are reusable it is undesirable to mark the sleeve pack in any permanent way. The next use of the sleeve pack assembly may involve entirely different contents than the current shipment.
It has therefore been an objective of this invention to provide a sleeve pack which solves all of these potential problems.
Specifically, it has been an objective of this invention to provide a sleeve pack which has both stacking strength and side impact resilience.
It has been another objective of the present invention to provide a sleeve pack made of a continuous single ply of multiple ply board which fits snuggly inside the outer channel of the pallet base of a sleeve pack assembly.
It has been another objective of this invention to provide a sleeve pack which does not have overlapping sidewall panels but rather has adjacent sidewall panels joined together in the same plane in an edge-to-edge relationship so as to eliminate all of the problems associated with overlapping sidewall panels.
It has been another objective of the present invention to provide a sleeve pack which may be relatively inexpensively assembled from one continuous piece of corrugated plastic.
It has been yet another objective of the present invention to provide a sleeve pack assembly whose contents may be easily identified from a distance without disassembling or opening the sleeve pack.